Movement sensation (kinesthesia) plays an important role in movement performance. It orients the central nervous system about the limb position in space as well as direction and degree of the movement. Kinesthesia is provided by muscle, cutaneous, and joint receptors. The relative contribution of each of these receptors in kinesthetic information varies from the small to the large joint and from proximal to distal limb segment. Even in the distal limb joint, Kinesthesia in the hand is supported by higher, enriched corticalization function than in foot joints. Thumb movement is the most controlled kinesthetically supported limb segment in man. Skilled movement such as writing and other manipulative tasks depend entirely on the kinesthetic information of thumb movement. Current information about kinesthesia comes mainly from large joints or the distal interphalangeal joint of the thumb in normal adult subjects and determine what influence the subject's age has on the level. This will determine the cause of the changes in movement dexterity that accompany the aging process. It will be reflected in the causes of frequent falls in the elderly as a result of shifting in movement kinesthesia. The relative contribution of the muscle, cutaneous, and joint receptors in the kinesthetic information of the thumb will also be studied and results will be related to the first part of this project. These studies are of considerable health significance especially in the evaluation and rehabilitation methodologies of patients with neuromuscular problems of the hand. This application is for the support of two graduate and two undergraduate students to participate in an on- going NIH-funded research project. the novelty of the technique and extensive health application of the results in rehabilitation and aging provide a unique environment for fostering research interest among graduate and undergraduate students in the field of rehabilitation.